Disco L475 IOT01 (B-L475E-IOT01A)

Overview

The B-L475E-IOT01A Discovery kit for IoT node allows users to develop applications with direct connection to cloud servers. The Discovery kit enables a wide diversity of applications by exploiting low-power communication, multiway sensing and ARM® Cortex®-M4 core-based STM32L4 Series features.

This kit provides:

64-Mbit Quad-SPI (Macronix) Flash memory
Bluetooth® V4.1 module (SPBTLE-RF)
Sub-GHz (868 or 915 MHz) low-power-programmable RF module (SPSGRF-868 or SPSGRF-915)
Wi-Fi® module Inventek ISM43362-M3G-L44 (802.11 b/g/n compliant)
Dynamic NFC tag based on M24SR with its printed NFC antenna
2 digital omni-directional microphones (MP34DT01)
Capacitive digital sensor for relative humidity and temperature (HTS221)
High-performance 3-axis magnetometer (LIS3MDL)
3D accelerometer and 3D gyroscope (LSM6DSL)
260-1260 hPa absolute digital output barometer (LPS22HB)
Time-of-Flight and gesture-detection sensor (VL53L0X)
2 push-buttons (user and reset)
USB OTG FS with Micro-AB connector
Expansion connectors:
- Arduino™ Uno V3
- PMOD
Flexible power-supply options:
- ST LINK USB VBUS or external sources
On-board ST-LINK/V2-1 debugger/programmer with USB re-enumeration capability:
- mass storage, virtual COM port and debug port

More information about the board can be found at the Disco L475 IoT1 website.

Hardware

The STM32L475VG SoC provides the following hardware IPs:

Ultra-low-power with FlexPowerControl (down to 120 nA Standby mode and 100 uA/MHz run mode)
Core: ARM® 32-bit Cortex®-M4 CPU with FPU, frequency up to 80 MHz, 100DMIPS/1.25DMIPS/MHz (Dhrystone 2.1)
Clock Sources:
- 4 to 48 MHz crystal oscillator
- 32 kHz crystal oscillator for RTC (LSE)
- Internal 16 MHz factory-trimmed RC ( ±1%)
- Internal low-power 32 kHz RC ( ±5%)
- Internal multispeed 100 kHz to 48 MHz oscillator, auto-trimmed by LSE (better than ±0.25 % accuracy)
- 3 PLLs for system clock, USB, audio, ADC
RTC with HW calendar, alarms and calibration
Up to 24 capacitive sensing channels: support touchkey, linear and rotary touch sensors
16x timers:
- 2x 16-bit advanced motor-control
- 2x 32-bit and 5x 16-bit general purpose
- 2x 16-bit basic
- 2x low-power 16-bit timers (available in Stop mode)
- 2x watchdogs
- SysTick timer
Up to 114 fast I/Os, most 5 V-tolerant, up to 14 I/Os with independent supply down to 1.08 V
Memories
- Up to 1 MB Flash, 2 banks read-while-write, proprietary code readout protection
- Up to 128 KB of SRAM including 32 KB with hardware parity check
- External memory interface for static memories supporting SRAM, PSRAM, NOR and NAND memories
- Quad SPI memory interface
4x digital filters for sigma delta modulator
Rich analog peripherals (independent supply)
- 2x 12-bit ADC 5 MSPS, up to 16-bit with hardware oversampling, 200 uA/MSPS
- 2x 12-bit DAC, low-power sample and hold
- 2x operational amplifiers with built-in PGA
- 2x ultra-low-power comparators
18x communication interfaces
- USB OTG 2.0 full-speed, LPM and BCD
- 2x SAIs (serial audio interface)
- 3x I2C FM+(1 Mbit/s), SMBus/PMBus
- 6x USARTs (ISO 7816, LIN, IrDA, modem)
- 3x SPIs (4x SPIs with the Quad SPI)
- CAN (2.0B Active) and SDMMC interface
- SWPMI single wire protocol master I/F
14-channel DMA controller
True random number generator
CRC calculation unit, 96-bit unique ID
Development support: serial wire debug (SWD), JTAG, Embedded Trace Macrocell™

More information about STM32L475VG can be found here:

Supported Features

The disco_l475_iot1 board supports the hardware features listed below.

on-chip / on-board: Feature integrated in the SoC / present on the board.
2 / 2: Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo: Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

disco_l475_iot1

/

stm32l475xx

Type	Location	Description	Compatible
CPU	on-chip	ARM Cortex-M4F CPU1	`arm,cortex-m4f`
ADC	on-chip	STM32 ADC1 2	`st,stm32-adc`
Bluetooth	on-board	STMicroelectronics SPI protocol V1 compatible with BlueNRG-MS devices1	`st,hci-spi-v1`
CAN	on-chip	STM32 CAN controller1	`st,stm32-bxcan`
Clock control	on-chip	STM32 RCC (Reset and Clock controller)1	`st,stm32-rcc`
	on-chip	STM32 HSE Clock1	`st,stm32-hse-clock`
	on-chip	Generic fixed-rate clock provider2	`fixed-clock`
	on-chip	STM32 MSI Clock1	`st,stm32-msi-clock`
	on-chip	STM32 LSE Clock1	`st,stm32-lse-clock`
	on-chip	STM32L4/L5 main PLL1	`st,stm32l4-pll-clock`
	on-chip	STM32 Microcontroller Clock Output (MCO)1	`st,stm32-clock-mco`
Counter	on-chip	STM32 counters9	`st,stm32-counter`
DAC	on-chip	STM32 family DAC1	`st,stm32-dac`
DMA	on-chip	STM32 DMA controller (V2)1 1	`st,stm32-dma-v2`
Flash controller	on-chip	STM32 Family flash controller1	`st,stm32-flash-controller`
Flash controller	on-board	STM32 QSPI Flash controller supporting the JEDEC CFI interface1	`st,stm32-qspi-nor`
GPIO & Headers	on-chip	STM32 GPIO Controller8	`st,stm32-gpio`
GPIO & Headers	on-board	GPIO pins exposed on Arduino Uno (R3) headers1	`arduino-header-r3`
I2C	on-chip	STM32 I2C V2 controller3	`st,stm32-i2c-v2`
Input	on-board	Group of GPIO-bound input keys1	`gpio-keys`
Interrupt controller	on-chip	ARMv7-M NVIC (Nested Vectored Interrupt Controller)1	`arm,v7m-nvic`
Interrupt controller	on-chip	STM32 External Interrupt Controller1	`st,stm32-exti`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
LED	on-board	Group of PWM-controlled LEDs1	`pwm-leds`
Memory controller	on-chip	STM32 Battery Backed RAM1	`st,stm32-bbram`
MMC	on-chip	STM32 SDMMC Disk Access1	`st,stm32-sdmmc`
MTD	on-chip	STM32 flash memory1	`st,stm32-nv-flash`
MTD	on-board	Fixed partitions of a flash (or other non-volatile storage) memory2	`fixed-partitions`
PHY	on-chip	This binding is to be used by all the usb transceivers which are built-in with USB IP1	`usb-nop-xceiv`
Pin control	on-chip	STM32 Pin controller1	`st,stm32-pinctrl`
Power management	on-chip	STM32 power controller1	`st,stm32-pwr`
PWM	on-chip	STM32 PWM2 7	`st,stm32-pwm`
QSPI	on-chip	STM32 QSPI Controller1	`st,stm32-qspi`
Reset controller	on-chip	STM32 Reset and Clock Control (RCC) Controller1	`st,stm32-rcc-rctl`
RNG	on-chip	STM32 Random Number Generator1	`st,stm32-rng`
RTC	on-chip	STM32 RTC1	`st,stm32-rtc`
Sensors	on-board	STMicroelectronics LIS3MDL magnetometer1	`st,lis3mdl-magn`
	on-board	STMicroelectronics HTS221 humidity and temperature sensor on I2C bus1	`st,hts221`
	on-board	STMicroelectronics LPS22HB pressure sensor1	`st,lps22hb-press`
	on-board	STMicroelectronics LSM6DSL 6-axis accelerometer and gyrometer accessed through I2C bus1	`st,lsm6dsl`
	on-board	STMicroelectronics VL53L0X Time of Flight sensor1	`st,vl53l0x`
	on-chip	STM32 family TEMP node for production calibrated sensors with two calibration temperatures1	`st,stm32-temp-cal`
	on-chip	STM32 VREF+1	`st,stm32-vref`
	on-chip	STM32 VBAT1	`st,stm32-vbat`
Serial controller	on-chip	STM32 USART1 2	`st,stm32-usart`
	on-chip	STM32 LPUART1	`st,stm32-lpuart`
	on-chip	STM32 UART1 1	`st,stm32-uart`
SMbus	on-chip	STM32 SMBus controller3	`st,stm32-smbus`
SPI	on-chip	STM32 SPI controller with embedded Rx and Tx FIFOs2 1	`st,stm32-spi-fifo`
SRAM	on-chip	Generic on-chip SRAM description1	`mmio-sram`
Timer	on-chip	ARMv7-M System Tick1	`arm,armv7m-systick`
	on-chip	STM32 timers2 9	`st,stm32-timers`
	on-chip	STM32 low-power timer (LPTIM)1 1	`st,stm32-lptim`
USB	on-chip	STM32 OTGFS controller1	`st,stm32-otgfs`
Watchdog	on-chip	STM32 watchdog1	`st,stm32-watchdog`
Watchdog	on-chip	STM32 system window watchdog1	`st,stm32-window-watchdog`
Wi-Fi	on-board	es-WiFi module1	`inventek,eswifi`

Connections and IOs

Disco L475 IoT Board has 8 GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.

Note that LED LD1 and SPI1 SCK use the same GPIO pin and cannot be used simultaneously.

Available pins:

For detailed information about available pins please refer to STM32 Disco L475 IoT1 board User Manual.

Default Zephyr Peripheral Mapping:

UART_1 TX/RX : PB6/PB7 (ST-Link Virtual Port Com)
UART_4 TX/RX : PA0/PA1 (Arduino Serial)
I2C1 SCL/SDA : PB8/PB9 (Arduino I2C)
I2C2 SCL/SDA : PB10/PB11 (Sensor I2C bus)
I2C3 SCL/SDA : PC0/PC1
SPI1 NSS/SCK/MISO/MOSI : PA2/PA5/PA6/PA7 (Arduino SPI)
SPI3 SCK/MISO/MOSI : PC10/PC11/PC12 (BT SPI bus)
PWM_2_CH1 : PA15
PWM_15_CH1 : PB14 (LD2)
USER_PB : PC13
LD1 : PA5 (same as SPI1 SCK)
LD2 : PB14
ADC12_IN5 : PA0
ADC123_IN3 : PC2
ADC123_IN4 : PC3
ADC12_IN13 : PC4
ADC12_IN14 : PC5
DAC1_OUT1 : PA4

System Clock

Disco L475 IoT System Clock could be driven by internal or external oscillator, as well as main PLL clock. By default System clock is driven by PLL clock at 80MHz, driven by 16MHz high speed internal oscillator.

Serial Port

Disco L475 IoT board has 6 U(S)ARTs. The Zephyr console output is assigned to UART1. Default settings are 115200 8N1.

Programming and Debugging

Disco L475 IoT board includes an ST-LINK/V2-1 embedded debug tool interface.

Applications for the disco_l475_iot1 board configuration can be built and flashed in the usual way (see Building an Application and Run an Application for more details).

Flashing

The board is configured to be flashed using west STM32CubeProgrammer runner, so its installation is required.

Alternatively, OpenOCD or JLink can also be used to flash the board using the --runner (or -r) option:

$ west flash --runner openocd
$ west flash --runner jlink

Flashing an application to Disco L475 IoT

Here is an example for the Hello World application.

Connect the Disco L475 IoT to your host computer using the USB port, then run a serial host program to connect with your Nucleo board. For example:

$ minicom -D /dev/ttyACM0

Then build and flash the application:

# From the root of the zephyr repository
west build -b disco_l475_iot1 samples/hello_world
west flash

You should see the following message on the console:

$ Hello World! arm

Debugging

You can debug an application in the usual way. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b disco_l475_iot1 samples/hello_world
west debug